<?php

/*
* 打赏小程序微信支付
*/

class WeixinPay
{

    protected $appid;
    protected $mch_id;
    protected $key;
    protected $openid;
    protected $out_trade_no;
    protected $body;
    protected $total_fee;

    function __construct($appid, $openid, $mch_id, $key, $out_trade_no, $body, $total_fee)
    {
        $this->appid = $appid;
        $this->openid = $openid;
        $this->mch_id = $mch_id;
        $this->key = $key;
        $this->out_trade_no = $out_trade_no;
        $this->body = $body;
        $this->total_fee = $total_fee;
    }

    public function pay()
    {
//统一下单接口
        $return = $this->weixinapp();
        return $return;
    }


//统一下单接口
    public function unifiedorder()
    {
        $url = 'https://api.mch.weixin.qq.com/pay/unifiedorder';
        $parameters = array(
            'appid' => $this->appid, //小程序ID
            'mch_id' => $this->mch_id, //商户号
            'nonce_str' => $this->createNoncestr(), //随机字符串
            'body' => $this->body,
            'out_trade_no' => $this->out_trade_no,
            'total_fee' => $this->total_fee,
            'spbill_create_ip' => $_SERVER['REMOTE_ADDR'], //终端IP
            'notify_url' => 'https://reward.test.hbbeisheng.com/api/notify.php', //通知地址  确保外网能正常访问
            'openid' => $this->openid, //用户id
            'trade_type' => 'JSAPI'//交易类型
        );
//统一下单签名
        $parameters['sign'] = $this->getSign($parameters);
        $xmlData = $this->arrayToXml($parameters);
        $return = $this->xmlToArray($this->postXmlCurl($xmlData, $url, 60));
        return $return;
    }


    public static function postXmlCurl($xml, $url, $second = 30)
    {
        $ch = curl_init();
//设置超时
        curl_setopt($ch, CURLOPT_TIMEOUT, $second);
        curl_setopt($ch, CURLOPT_URL, $url);
        curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, FALSE);
        curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, FALSE); //严格校验
//设置header
        curl_setopt($ch, CURLOPT_HEADER, FALSE);
//要求结果为字符串且输出到屏幕上
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, TRUE);
//post提交方式
        curl_setopt($ch, CURLOPT_POST, TRUE);
        curl_setopt($ch, CURLOPT_POSTFIELDS, $xml);
        curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 20);
        curl_setopt($ch, CURLOPT_TIMEOUT, 40);
        set_time_limit(0);
//运行curl
        $data = curl_exec($ch);
//返回结果
        if ($data) {
            curl_close($ch);
            return $data;
        } else {
            $error = curl_errno($ch);
            curl_close($ch);
            throw new WxPayException("curl出错，错误码:$error");
        }
    }


//数组转换成xml
    public function arrayToXml($arr)
    {
        $xml = "<xml>";
        foreach ($arr as $key => $val) {
            if (is_array($val)) {
                $xml .= "<" . $key . ">" . arrayToXml($val) . "</" . $key . ">";
            } else {
                $xml .= "<" . $key . ">" . $val . "</" . $key . ">";
            }
        }
        $xml .= "</xml>";
        return $xml;
    }


//xml转换成数组
    public function xmlToArray($xml)
    {
//禁止引用外部xml实体
        libxml_disable_entity_loader(true);
        $xmlstring = simplexml_load_string($xml, 'SimpleXMLElement', LIBXML_NOCDATA);
        $val = json_decode(json_encode($xmlstring), true);
        return $val;
    }


//微信小程序接口
    public function weixinapp()
    {
//统一下单接口
        $unifiedorder = $this->unifiedorder();
//        print_r($unifiedorder);
        $parameters = array(
            'appId' => $this->appid, //小程序ID
            'timeStamp' => '' . time() . '', //时间戳
            'nonceStr' => $this->createNoncestr(), //随机串
            'package' => 'prepay_id=' . $unifiedorder['prepay_id'], //数据包
            'signType' => 'MD5'//签名方式
        );
//签名
        $parameters['paySign'] = $this->getSign($parameters);
        return $parameters;
    }


//作用：产生随机字符串，不长于32位
    public function createNoncestr($length = 32)
    {
        $chars = "abcdefghijklmnopqrstuvwxyz0123456789";
        $str = "";
        for ($i = 0; $i < $length; $i++) {
            $str .= substr($chars, mt_rand(0, strlen($chars) - 1), 1);
        }
        return $str;
    }

//作用：生成签名
    public function getSign($Obj)
    {
        foreach ($Obj as $k => $v) {
            $Parameters[$k] = $v;
        }
//签名步骤一：按字典序排序参数
        ksort($Parameters);
        $String = $this->formatBizQueryParaMap($Parameters, false);
//签名步骤二：在string后加入KEY
        $String = $String . "&key=" . $this->key;
//签名步骤三：MD5加密
        $String = md5($String);
//签名步骤四：所有字符转为大写
        $result_ = strtoupper($String);
        return $result_;
    }


///作用：格式化参数，签名过程需要使用
    public function formatBizQueryParaMap($paraMap, $urlencode)
    {
        $buff = "";
        ksort($paraMap);
        foreach ($paraMap as $k => $v) {
            if ($urlencode) {
                $v = urlencode($v);
            }
            $buff .= $k . "=" . $v . "&";
        }
        $reqPar = '';
        if (strlen($buff) > 0) {
            $reqPar = substr($buff, 0, strlen($buff) - 1);
        }
        return $reqPar;
    }

    /* *
     * 微信支付回调验签
     */
    public function verify($data, $sign = null, $sync = false)
    {
        $data = $this->fromXml($data);

        $sign = is_null($sign) ? $data['sign'] : $sign;

        return $this->getVerifySign($data) === $sign ? $data : false;
    }

    protected function fromXml($xml)
    {
        if (!$xml) {
            //throw new InvalidArgumentException('convert to array error !invalid xml');
            return '';
        }

        libxml_disable_entity_loader(true);

        return json_decode(json_encode(simplexml_load_string($xml, 'SimpleXMLElement', LIBXML_NOCDATA), JSON_UNESCAPED_UNICODE), true);
    }

    protected function getVerifySign($data)
    {
        if (is_null($this->key)) {
            return '';
        }

        ksort($data);

        $string = md5($this->getSignContent($data).'&key='.$this->key);

        return strtoupper($string);
    }

    protected function getSignContent($data)
    {
        $buff = '';

        foreach ($data as $k => $v) {
            $buff .= ($k != 'sign' && $v != '' && !is_array($v)) ? $k.'='.$v.'&' : '';
        }

        return trim($buff, '&');
    }

}

?>